Forestle's business model is both simple and noble. The site offers a typical search engine box and displays a list of blue links for results (points are deducted for not using green links), and all revenue after administration expenses (a mere ten percent of its income) is donated to The Nature Conservancy's adopt an acre program. When the site launched out of beta on August 25, 2008, it displayed a running tally on its main page of how many square yards Forestle users have saved, and offered plug-ins for the search bars of Firefox, Safari, and Opera to help users get their green conservation on.

A mere four days later on September 1, however, Google abruptly ended its partnership with Forestle under suspicion that the green engine offered "incentives to click artificially on sponsored links." The company asked users and bloggers to stomp their feet and convince Google to reconsider, though it also stated on its home page its belief that Google "ended the partnership because Forestle became too successful." Regardless, Google apparently never had a change of heart, so Forestle forged a two-year partnership with Yahoo and is back with a handful of noteworthy changes.

Key to Forestle's cause, the engine's About page now displays monthly reports of Forestle's donations, stretching back to the organization's original August launch. So far Forestle's users have managed to search enough to protect 15 acres of the Osa Penninsula of Costa Rica. This transparency will likely be appreciated by users, though it is worth noting that no actual monetary amounts are tallied in these reports.

January's donation should be considerably higher, however, since as of this writing, Forestle's users have protected 69,817 square meters of forest.

Interestingly, other links on Forestle's site have not been switched from Google to Yahoo services. The Google-like toolbar along the top still links to Google's image, map, news, and groups services, as well as YouTube, Wikipedia, and Znout, another purportedly eco-friendly search engine that uses black backgrounds to reduce the amount of light needed to display the page.